Laminated gypsum core-board



y 5,1959 1 R. G. VBUERGIJN E AL 2,884,779 LAMINATED GYPSUM CORE-BOARD Filed Aug. 31, 1953 INVENTORS- R ing G. Bue rgm BY3J0fznKH0vJ12d 3 34 mzyw ATTORNEY.

United States Patent LAMINATED GYPSUM CORE-BOARD Rodney G. Buergin, Snyder, and John K. Hovind, Buffalo, N.Y., assignors to The National Gypsum Com pany, Buffalo, N.Y., a corporation of Delaware Application August 31, 1953,'Serial No. 377,482

3 Claims. (Cl. 72-16) This invention relates to a gypsum core-board construction and particularly to a core-board with staggered edge laminations having interlocking edges thereon. The invention'is of particular advantage and is especially directed to a gypsum core-board construction for use as the central core portion in the fabrication of non-bearing dry wall interior partitions.

The characteristics of major importance in the fabrication of non-bearing partitions having a central core of laminated gypsum core-boards include strength, fire resistance, facility of erection, and sound proofing. The present invention is concerned primarily with strength and fire resistance, and simultaneously provides a marked improvement in facility of erection and soundproofing.

With regard to fire resistance of partitions, substantially all fire resistance ratings are established by tests conducted in accordance with the Standard for Fire Test of Building Construction and Materials (ASTM-E119). The most common ratings required by'building codes are the threequarterhour, one-hour and two-hour ratings. Building codes will normally specify either the three-quarter'hour, one-hour or the two-hour rating depending on the particular conditions, i.e. a one-hour rated partition between adjacent rooms and a two-hour rated partition adjacent a long hallway or elevator shaft.

In the particular type of partition concerned-herein, the non-bearing, solid, gypsum partition, there is no known construction which, in the standard two-inch thickness,

has achieved the two-hour fire rating.

the core ply edges to be in-line, precluding staggered laminations, The above said need of various junction devices is, furthermore, a disadvantage on the grounds of cost, material handling and complication of the erection of thepartition.

It is, therefore, a principal object ofthis invention to provide a non-bearing, laminated, gypsum core-board which, when fabricated into a standard two-inch thick non-bearing partition, will meet the requirements of a twohour fire resistance rating. It is also an object of this invention to provide such a fire resistant, laminated coreboard, which will contribute suitable impact strength to the completed partition without the use of any of the above-mentioned junction devices for providing such strength.

A further object of the invention is to provide simplicity in the fabrication of anon-bearing partition comprising laminated, gypsum core-boards.

A still further. object. is to provide a laminated, gypsum core-board which will. contribute. substantially to improved soundproofing qualities of the completed partition.

2 Briefly the above objects are accomplished by providing a laminated, gypsum board having staggered edges with perpendicularly interlocking edge profiles.

These and other objects and advantages will appear more fully when considered in connection with the follow- ,ner portion of Fig. 1.

Fig.2 is a perspective end view of a laminated gypsum core-board, showing the preferred form of the invention.

Fig. 3 is a perspective end view of a modified form of the invention.

Fig. 4 is sectional view with exaggerated thickness of a finished partition including the novel laminated core-board of Fig. 2.

Referring now to Fig. 1, there is shown an outside wall 10 of a room or building in which room there is partially constructed, in accordance with the invention, a nonbearing partition 11, i.e. without wall studs. The drawing includes two novel laminated, gypsum core-boards 12, it being apparent that further successive core-boards would be similarly inserted and abutted therewith throughout the desired extent of partition '11.

Core-boards 12 are maintained and held up at the base thereof in a continuous standard base runner 15, and at the top thereof in a pair of continuous standard ceiling run- .ners 16, 16, as are respectively shown in Figs. 1a and lb, it beingunderstood that the invention is not to be limited to the particular runner constructions here shown. Short sections of ceiling runners 16, .16, not shown, are disposed at spaced intervals along the junction of partition 11 and outside wall 10 to provide impact strength at the partition ends. Standard outer gypsum wallboards 17, 17, are adhered withcement 18 to both faces of the laminated coreboard 12 it beingunderstood that a coat of plaster on each face, or otherequivalent egual in thickness to wallboards 17, would be satisfactory and within the scope of the invention. Casein types of cement are preferred at 18 for the on-the-job application of wallboard 17 to core 12, although other comparable cements are considered suitable and adequate. With the use of the outer gypsum wallboard 17, the joints thereof are necessarily staggered relative to the joints of the laminated core-board 12 and relative to the jointof the opposite face Wal1board'17 to provide the optimum'fire retardant qualities. The ceiling angle is finished with tape joint system 19 applied on each sideof partition 11 at the ceiling junction to provide a desired finished appearance.

The core-board *12 is comprised of two lamented plies 20, 20 of gypsum board. 'Each ply 20 is composed of the usual gypsum stuccoenclosed on each-face and each lateraledge with a standard gypsum board paper 21. .Lateral edges 22, 22 of each ply 20 are bevelled in the order of 60 to the core-board face, parallel one to the other and parallel one ply 'to the other. adhered face to face with a'suitable laminating cement The plies 20, 20 are ,steppedvin ply-edge is at the interface 25 spaced substantially from theedge of the stepped-out ply. Thus a stronginterlocking joint is obtained when core edge 3 24 is abutted with the complementary edge of a like laminated core-board 12.

In Fig. 4, a greatly exaggerated thickness to width view of a fabricated portion of partition 11 is effective in illustrating the relation of the joints of the laminated core-boards 12 and the outer wallboards 17, the factory applied cement 23, and the on-the-job applied cement 18. The outer surfaces of the outer wallboards 17 are slightly bevelled adjacent the edges thereof and the joints sealed and the bevelled edges filled in a manner wellknown in the art as the tape joint system. A tape joint system 26, similar in structure to tape joint system 19, is shown at each outer wall board joint, and consists of a two-inch wide paper tape embedded in a standard joint cement.

In order to provide a two-hour fire rated two-inch solid gypsum partition, the partition 11 is constructed of laminated core-boards 12 of two half-inch thick plies, two foot wide and ceiling height. The outer wallboards 17 are of half-inch thickness, four foot wide and also full room height. Despite shrinkage which may occur in the core-boards 12 when exposed to fire, there will be, because of the shiplap joint 24, at least /2 inch, or one ply, preventing the passage of flames and retarding the transmission of heat to the back or unexposed outer wallboard 17. Prior two-inch laminated partitions, having the squared or in-line core ply edges, failed to achieve a two-hour fire rating due to reaching maximum temperatures prematurely at the unexposed surface opposite the in-line core joints.

The strength afforded by the slant edge shiplap interlocking core joint 24 will be apparent from a study of Fig. 4. A pair of the interlocking laminated core-boards 12 is a more homogeneous unit than a pair of core-boards with square edges held together by mechanical fasteners. The more homogeneous pair of laminated core-boards 12 have a far greater tendency to distribute the force of an impact load over a greater area of the completed partition, especially when the load is concentrated at or near a core joint. The simplicity of erection of the partition, with the use of the novel core edges, is apparent from the drawings and above description.

Sound tests conducted on a partition built in accordance with and embodying the invention have disclosed that the sound insulation is substantially greater than prior nonbearing laminated gypsum core-board partitions of equal thickness. This improvement in sound insulation is the result of providing suitable means for constructing the paltition without metal fasteners which would have high sound conductivity, and without adjacent ply joints continuous or in line which would create a sounding box efiect directly through two plies of thickness.

Referring now to Fig. 3, there is indicated by the numeral 30, one modified form of the interlocking, laminated core wallboard, which is formed in one of the relatively few profiles to which a gypsum wall board is susceptible to forming. Two plies 31, 31 are adhered face to face with cement 23, laterally staggered in the order of inch to provide shiplap joints 32, 32 at the lateral edges thereof. At the respective core board edges there are formed in each ply, convex V-shaped edges 33 and concave V-shaped edges 34 respectively in each opposite edge with complementary 120 angles within the V.

The fabrication of core-board 30 into a partition is identical to that described above for the fabrication partition 11. The numerous advantages and theories also discussed above relative to laminated core wallboard 12, apply equally to coreboard 30.

Having completed a detailed disclosure of the preferred embodiments of our invention so that those skilled in the art may practice the same, we contemplate that variations may be made without departing from the scope of the invention as defined in the appended claims.

We claim:

1. A two-ply gypsum core board unit consisting solely of first and second plies of gypsum board free of metallic fastening elements, each of said plies having a pair of opposite lateral side faces and a pair of substantially planar opposite end faces connecting adjacent edges of said side faces and extending throughout the length of said edges, one side face of said first ply being firmly adhesively bonded 'to one side face of said second ply, one end face of said first ply defining an outer end face at one end of said unit, one end face of said second ply defining an inner end face at said one end of said unit, the opposite end face of said second ply defining an outer end face at the opposite end of said unit, the opposite end face of said first ply defining an inner end face at said opposite end of said unit, the inner end face at each end of said unit being spaced inwardly of the adjacent outer end face of said unit, the side face extending between the adjacent inner and outer end faces defining a free marginal side face portion at each end of said unit along the edge of the ply having the outer end face, each of said end faces defining an acute angle with the adjacent free marginal side face portion, all of said angles being substantially similar.

2. An improved, fire-retardant, solid, gypsum coreboard partition comprising a plurality of core-board units disposed alongside one another in a central plane of said partition, each of said units consisting solely of first and second plies of gypsum board free of metallic fastening elements, each of said plies having a pair of opposite lateral side faces and a pair of substantially planar 0pposite end faces connecting adjacent edges of said side faces and extending throughout the length of said edges, one side face of said first ply being firmly adhesively bonded to one side face of said second ply, a covering material bonded to the opposite side face of each of said first and second plies, one end face of said second ply defining an inner end face at one end of said unit, one end face of said second ply defining an inner end face at said one end of said unit, the opposite end face of said second ply defining an outer end face at the opposite end of said unit, the opposite end face of said first ply defining an inner end face at said opposite end of said unit, the inner face at each end of said unit being spaced inwardly of the adjacent outer end face of said unit, the side face extending between the adjacent inner and outer end faces defining a free marginal side face portion at each end of each unit along the edge of the ply having the outer end face, each of said end faces defining an acute angle with the adjacent free marginal side face portion, all of said angles being substantially similar, the adjacent ends of each of said units being disposed in overlapping relationship with the free marginal side face portions of adjacent units being in opposed facing relationship, the outer end face-of each unit being positioned closely adjacent to and in substantially parallel relationship with the inner end face of the adjacent unit.

3. An improved, fire-retardant, solid, gypsum coreboard partition comprising a plurality of core-board units disposed alongside one another in a central plane of said partition, each of said units consisting solely of first and second plies of gypsum board free of metallic fastening elements, each of said plies having a pair of opposite lateral side faces and a pair of substantially planar opposite end faces connecting adjacent edges of said side faces and extending throughout the length of said edges, one side face of said first ply being firmly adhesively bonded to one side face of said second ply, a wall board bonded to the opposite side face of each of said first and second plies, one end face of said second ply defining an inner end face at one end of said unit, one end face of said second ply defining an inner end face at said one end of said unit, the opposite end face of said second ply defining an outer end face at the opposite end of said unit, the oppositeend face of said first ply defining an inner end face at said opposite end of said unit, the inner face at each end of said unit being spaced inwardly of the adjacent outer end face of said unit, the side face extending between the adjacent inner and outer end faces defining a free marginal side face portion at each end of each unit along the edge of the ply having the outer end face, each of said end faces defining an acute angle with the adjacent free marginal side face portion, all of said angles being substantially similar, the adjacent ends of each of said units being disposed in overlapping relationship with the free marginal side face portions of adjacent units being in opposed facing relationship, the outer end face of each unit being positioned closely adjacent to and in substantially parallel relationship with the inner end face of the adjacent unit, 15

the lateral edges of said wall boards on adjacent units being disposed in edge-to-edge relationship, the joints defined by adjacent wall board edges and end faces of the units all being staggered relative to one another.

References Cited in the file of this patent UNITED STATES PATENTS 2,110,488 Justement Mar. 8, 1938 2,276,071 Scull Mar. 10, 1942 2,283,582 Scherer May 19, 1942 2,305,247 Fisher Dec. 15, 1942 2,314,449 Hoggatt Mar. 23, 1943 2,381,635 Baker Aug. 7, 1945 2,505,903 Madger May 2, 1950 FOREIGN PATENTS 540,302 Great Britain of 1941 541,733 Great Britain of 1941 

